Procedures using what is commonly known as the “Beer-Lambert Law,” (often just called “Beer's Law”) are well known, which law states that, for a fixed path length, the absorbance of a solution is proportional to the concentration of the absorbing analyte, which allows us to determine the concentration of an absorbing analyte in an unknown sample.
In hydrocarbon wells, production logging tools often incorporate various sensors, instruments and control devices in order to carry out any number of downhole operations. Thus, the tools may include sensors and/or electronics for formation evaluation, fluid analysis, and so on. Tools that allow testing of fluid properties using instruments located downhole are also known.